DISEASES OF THE FETLOCK, ANKLE, AND FOOT. 461 



osteuni membrane covering the bone and coffin bone also are subjects 

 of the inflammatory process. Neither is this all; in some of these 

 cases of peditis acute inflammation of the coffin joint is present, and 

 occasionally suppuration of the joint. A mild form of periostitis, 

 in which the exudation is in the outer layer of the periosteum only, 

 is a more common condition than, is recognized generally by practi- 

 tioners. Intimate contiguity of structures is the predisposing cause, 

 for the disease either spreads from the original seat or the complica- 

 tion occurs as one of the primary results of the exciting cause. In 

 the severer cases in which the exudate separates the periosteum from 

 the bone, suppuration, gangrene, and superficial caries are common 

 results. If infiltration of the bone tissues is rapid the blood supply 

 is cut off by pressure upon the vessels and death of the coffin bone 

 follows. Grave constitutional symptoms mark these changes, which 

 soon prove fatal. 



In the mild cases of periostitis it is by no means easy positively to 

 determine its presence, for there are no special symptoms by which it 

 may be distinguished from pure laminitis. In a majority of acute 

 cases, though, which show no signs of improvement by the fifth to 

 seventh day, it is safe to suspect periostitis, particularly if the coro- 

 nets are very hot, the pulse full and hard, and the lameness acute. 

 In the fortunately rare cases in which the bone is affected with in- 

 flammation and suppuration the agony of the patient is intense; he 

 occupies the recumbent position almost continually, never standing 

 for more than a few minutes at a time ; suffers from the most care- 

 ful handling of the affected feet; maintains a rapid pulse and respi- 

 ration, high temperature, loss of appetite, and great thirst. It is in 

 these cases that the patient continually grows worse, and the appear- 

 ance of suppuration at the top of the hoof in about two weeks after 

 the inception of the disease proves the inefficiency of any treatment 

 which may have been used and the hopelessness of the case. These 

 patients die usually between the tenth and twentieth days either from 

 exhaustion or pyemic infection. 



Gangrene occurs in the periosteum as the result of excessive de- 

 tachment from the bone and compression due to excessive exuda- 

 tion. Other parts of the sensitive tissues are subject occasionally to 

 the same fate, and at times large areas will be found dead. 



Pumiced sole is that condition in which the horny sole in the neigh- 

 borhood of the toe readily cruifibles away and leaves the sensitive 

 tissues more or less exposed. It is not a complication of laminitis 

 only, for it is seen under other conditions. Williams has described 

 the homy tissue of pumiced sole as " weak, cheesy, or spongy, like 

 macerated horn, or even grumous (thick, clotted)." Crumbling horn, 

 when critically iexamined, shows almost an entire absence of the 

 cohesive matter which unites the healthy fibers, while the fibers them- 



